Signaling.



R. A. FESSENDEN. SIGNALING. APPLICATION FILED NOV.17, 1906.

. The form of receiver il 1,5 very UNIT-iin STATES PATENT carica.V

l REGINALD A. riissiiNDEN7 or WASHINGTON, DISTRICT or COLUMBIA.

sIeNaLING.

Application ma November 17, i9o5. seal N. 2s7,s54.

To all whom it may comm: e l Be it .known that I, REciNALn A. Fassi-:N- nEN, citizen of the United States, and resident of lvashington, District of Columbia, have invented certain new and Auseful Improvements in Signaling, of which the folowing is a specification.

The invention' described herein relates to certain improvements in receivers .for elecl10 tromagnet-ic waves of the class or kind described and claimed in Reissue Letters lPatent 12,115 and especially tothe receivers ofthe type shown in Figure Bof said patent.

Iustrated in Fig. 3

reliable and sensitive inoperation but is liable at times of being rendered inopera- ';tiv e by the choking up of the minute hole in the diaphragm by minute particles of dirt. It has also been found that very heavy discharges have atendency to enlarge the hole.

The object of the present invention is to provide suitable means whereby the receiver is rendered more sensitive and reliable and also to prevent by the use of suitable mai terial the enlargement of the perforation through heavy discharges.

The invention is hereinafter more fully described and claimed.

In the accompanying drawings forming a part of this specification Fig. l is a sectional elevation of the receiver embodying my improvements and Fig. 2 shows a method of'rconnecting the receiver in a circuitI which is especially applicable in making exact measurements on wave lengths.

In the practice of my invention the chamber or receptacle 1 which may be made of hard rubber or other suitable `material is provided at a suitable pointLin its length 40 with a diaphragm 2 formed of hard rubber.

Through this diaphragm-V is formed a perforation having its wall formed of highly refractory non-conducting material. This is conveniently done by securing a diamond die suchlv as is used for drawing wire in the diaphragm or a perforated sheet of mica may be used in connection with some liquids.

The portion of the receptacle above the diaphragm is connected by thin tube 4 with a reservoir 5 for liquid which is preferably anacid or a solution of'metallic salts preferably alkali such for example as nitric-acid, hydrochloric-acid or caustic potash. The reservoir should be arranged at such a height above the receptacle as to maintain a considerable pressure of liquid so as toinsure a flow thereof through the opening of the diaphragm. The portion of the receptacle 1 below the dia-phragm is connected by a tube4 (3 with a vessel 7 having an overflow spout provided with suitable means for regulating the outflow of the liquid whereby to regulate the level of the liquid below the diaphragm. Terminals 8 and 9 preferably large and preferably formed of platinumiridiurn or suitable material extends into the receptacle 1 above aiid below the diaphragm as shown. Below the diaphragm the vessel ,is provided with an outlet tube 10 whereby 'slight particles of dirt or small bubbles of gas will be carried through the opening 2l and hence it preserves the receiver in a normal, operatin condition. It is also found that the polarity of the terminals 8 and 9 is of importance in this connection as the small p articles appear to be carried by the electric action of the current. The direction of this carriage varies with different liquids and The polarity empirically so arranged. that with a given liquid used the electrical carriage will tend to be in the direction opposite to the 'low of the liquid. The level of the liquid in the lower part of the receptacle 1 may be raised up until it touches t-lie opening of the diaphragm or may be maintained at a slightl lower level as shown. The results vary wit different liquids and with highly conducting liquids the level is preferably ke t low though this is not essential. This orm .of receiver is lespecially applicable for use in connection with the measurement of wave Specification of Letters ,Patent I Patented March 30, 1909. 4

vprobably with the character of the particles. of the terminals is therefore v lengths and in Fig. 2 is shown a suitable form of connections for such purpose. -The antenna 14 is grounded and an inductance 15, condenser 16 both preferably variable and the described receiver 17 areconnected as- I claim herein as my invention:

Vshown in circuit with the antenna. A large vcondenser 18 preferably has the metallic armature of the plates connected to the groundV lterminal and the two outer plates connected to the receiver and variable capacity respectively. An indicating-inechanlsm 20 such as the Paul microammeter, a potentiometer 19 and a battery 21 are operatively connected as shown to the aerial. When using this apparatus for the measurement of wave lengths the inductancc 15 or capacity 18 arefvaried until a maximum reading is obtained on the indicatingmechanism 20 and this maximum 1s obtained when the circuit f 15, 16 is in resonance with the received oscillations. By then reading the values ofthe inductance and capacitythe Wave length may be determined. High resistances 22 and 23 preferably in the form of incandescent, lamps are preferably placed in series ltory material, means for causing` having in combination a receptacle having a diaphragm rovided 4with a erforationhaving its wal formed of a hig ly. refrac- `a How of liqluid through the perforation and terminas connected to the stream of liquid on opposite sides of the diaphragm.

3. A receiver for 'electromagnetic waves having in lcombination a receptacle having a diaphragm provided with a diamondvwall perforation, means for causing a flow of liquid through the perforation andterminals connected to the stream of liquid on opposite sides of the diaphragm.

4. A'rece'iver for electromagnetic Waves hayin'f in combination a receptacle or vessel provided with a perforated diaphragm, a reservoir for liquid connected to the receptacle on one side of the diaphragm, a discharge passage connected to the receptacle on the opposite side of the diaphragm, means for regulating the level of the liquid on one side of the diaphragm and terminals adapted to'be connected to the liquid on opposite sides of the diaphragm.

Signed at- Brant Rock in the county of Plymouth and State of Massachusetts this eighth day of N ovember A. D. 1905.

REGINALD A. FESSENDEN. Witnesses:

DARWIN S. WoLoo'rT, Jnssrn E. BENT. 

